Fig. 1. Satellite-derived gravity field (gray) [Sandwell et al., 2014] and multibeam echo sounder (color) data were used to produce these maps of the MH370 search area in the southeast Indian Ocean. The relief models are shown in Sun-illuminated (shaded relief) mode. The inset map shows the MH370 search area that was mapped with multibeam echo sounding (shown in red). This map highlights the Southeast Indian Ridge (SEIR) and the Kerguelen Plateau, and it includes estimated spreading rates of the SEIR [Argus et al., 2011], lines delineating regions of approximately equal age (isochrons [Muller et al., 2008]), and interpretations of SEIR segments (I–VII [Small et al., 1999]). Other abbreviations are AAD, Australian-Antarctic Discordance; CIR, Central Indian Ridge; RTJ, Rodriguez Triple Junction; SWIR, Southwest Indian Ridge; WA, Western Australia. The larger map shows details of the ocean depth mapping effort using multibeam echo sounder bathymetry data. Locations of Deep Sea Drilling Project (Leg 26) and Ocean Drilling Program (Legs 121 and 183) Sites 255, 752 to 755, 1141, and 1142 are also indicated, as are the locations of Figures 2, 3, and 4. Click for larger image.